Quick-assembly breech plug for muzzleloader firearms

ABSTRACT

The invention relates to a quick-assembly breech plug for muzzleloader firearms, allowing a quick assembly and disassembly and being extremely practical, simple to manufacture and having a low cost, wherein said breech plug comprises a cylindrical body ( 1 ), configured to be internally coupled in a rear end ( 10 ′) of a barrel ( 10 ), and a head ( 6 ) configured to define a limit coupling position of the breech plug inside the barrel ( 10 ), wherein the cylindrical body ( 1 ) externally comprises a male thread ( 2 ) having at least two starts located close to a front end ( 3 ) of the breech plug, opposite the head ( 6 ), according to a plane perpendicular to an axis of revolution of the cylindrical body ( 1 ), said male thread ( 2 ) being configured to screw into a female thread ( 10 ″) located internally in the rear end ( 10 ′) of the barrel ( 10 ), preferably 4 screw ridges.

OBJECT OF THE INVENTION

The present invention relates to a quick-assembly breech plug formuzzleloader firearms, applicable in the arms industry, and morespecifically in the field of firearms for use in sports, allowing aquick and effective assembly and disassembly of the breech plug in therear end of the barrel, being an extremely practical breech plug whichis simple to manufacture and has a low cost, which allows its couplingin the barrel from any angular position.

BACKGROUND OF THE INVENTION

Firearms which are loaded through the muzzle of the firearm, usuallyknown as muzzleloader firearms, incorporate at the rear end of thebarrel, opposite the muzzle, a part referred to as breech plug which canbe disassembled from the barrel, having the functions of closing therear end of the barrel during its use, while at the same time it allowsthe ignition of the charge, likewise allowing accessing the inside ofthe barrel when it is disassembled for the purpose of performingoperations for cleaning said barrel.

The breech plug is currently fixed to the rear end of the barrel bymeans of a standard thread, said thread having a single start, theoperations for assembling and disassembling the breech plug in thebarrel therefore require considerable time since a considerable lengthof thread must be screwed or unscrewed, step by step, until achievingthe complete extraction or introduction of the breech plug between 12and 20 turns on average.

For the purpose of solving the problem set forth in the previousparagraph, there are quick-assembly breech plugs incorporating means toallow quickly disassembling the breech plug from the rear end of thebarrel. Said means consist of incorporating planar recessed grooves,like bevel edges, located in diametric opposition according to thelongitudinal direction of the threaded male body of the breech plug,said planar recessed grooves being provided to be axially inserted in acertain and tight angular position inside the barrel, for which saidgrooves are located in correspondence with complementary bevel edgeslocated internally in the barrel, allowing a quick introduction of thebreech plug in the barrel. Then, by means of a 90° rotation of thebreech plug, the latter is secured to the barrel by means of thethreaded coupling of the male thread located in the male body of thebreech plug, with a complementary toothing, like a female thread,located internally in the barrel.

The main drawback of these breech plugs is that their manufacture iscomplicated and expensive, since the machining of said recessed groovesand bevel edges in the previously threaded male body of the breech plugis required, in addition to having to precisely incorporate recesses andcomplementary toothing inside the barrel, requiring the breech plug tobe in a certain angular position before introducing it in the barrel,which delays the operations for assembling it, which furthermore requirethe use of suitable tools for screwing and unscrewing the breech plug.

In this sense, patent application no. US-2006/0248771-A1 relates to amuzzleloader firearm comprise a breech plug for quickly assembling thebreech plug in the barrel, being based on a bayonet-type system, whichincorporates teeth and grooves both in the barrel and in the breech plugconfigured to allow a coupling and uncoupling by means of 90° rotations,having as a drawback, in addition to those indicated above, the factthat considering the described coupling means it is extremely difficultto prevent firing gases from escaping through said clearances.

DESCRIPTION OF THE INVENTION

The present invention relates to a quick-assembly breech plug formuzzleloader firearms, which allows both assembling and disassemblingthe breech plug in the barrel in an extremely quick and effectivemanner, for the purpose of removing the breech plug to clean the loaderor to remove a charge housed in the barrel. Said quickness andeffectiveness are based on the breech plug of the invention requiringfor its assembly and/or disassembly a smaller number of rotations incomparison with the currently existing breech plugs, the thread of whichhas a single start. The breech plug of the invention is simple,practical and inexpensive to manufacture, not requiring complex meansfor coupling to the barrel, as in the case of bayonet-type couplings,and allowing its introduction from any angular position, without havingto be in a certain angular position for its introduction.

The quick-assembly breech plug for muzzleloader firearms proposed by theinvention comprises a cylindrical body configured to be internallytightly coupled in a rear end of a barrel. The breech plug likewisecomprises a head configured to define a limit coupling position of thebreech plug inside the barrel.

According to the invention, the cylindrical body comprises, externally,a male thread having at least two starts located close to a front end ofthe breech plug, opposite the head. Said starts of the male thread aredefined depending on the inclination of the thread fillet, being able tobe clearly identified at any point of the cylindrical body upon makingan imaginary section according to a plane perpendicular to an axis ofrevolution of said cylindrical body, being able to count in said planethe starts that the male thread has, preferably 4 threads, 3revolutions=12 screw ridges. This furthermore causes a large angle inthe screw threads allowing the quick detachment of the breech plug andbarrel, being able to be loosened or placed by hand without needingtools, except for cases of jamming due to dirt.

Said male thread is configured to screw into a female thread locatedinternally in the rear end of the barrel, allowing the coupling betweenthe breech plug and the barrel.

It is contemplated that the front end of the cylindrical body comprisesan end section without male thread, i.e., a smooth section, said smoothend section having at least one perimetric groove configured to house anO-ring seal configured to prevent firing gases from escaping through aclearance located between the cylindrical body and the barrel when thefirearm is fired and the breech plug is coupled in the barrel.

Likewise, the front located in correspondence with the front end of thebreech plug has a planar face increasing the resistance of the breechplug, for the purpose of withstanding the large actions to which it issubjected during the ignition of the firearm.

On the other hand, for the purpose of handling and operating the breechplug more comfortably and easily, the possibility of the head comprisinga side surface in which at least one blind hole is located iscontemplated, in which said blind hole is configured to house andreceive a tooth of a tool or implement like a key, said blind holereceiving the transmission of a torque coming from said tool to causethe screwing and/or unscrewing of the breech plug in the barrel (4orifices).

Likewise, it is contemplated that the side surface of the head isknurled in order to allow manually gripping the breech plug for itsoperation, preventing its slipping.

Finally, it is contemplated that the breech plug comprises an axiallycentered inner hole configured with a housing for the primer cap andarranged to transmit the ignition to the powder.

Therefore, according to the described invention, the quick-assemblybreech plug for muzzleloader firearms proposed by the invention is anadvance in the breech plugs used up until now, and fully andsatisfactorily solves the problems previously set forth in the sense ofallowing a quick and effective assembly and/or disassembly in the rearend of the barrel, being an extremely practical breech plug which issimple to manufacture and has a low cost, which allows its coupling inthe barrel from any angular position.

DESCRIPTION OF THE DRAWINGS

To complement the description which is being made and for the purpose ofaiding to better understand the features of the invention according to apreferred practical embodiment thereof, a set of drawings is attached asan integral part of said description, in which the following has beendepicted with an illustrative and non-limiting character:

FIG. 1 shows a perspective view, from the side of the head, of thequick-assembly breech plug for muzzleloader firearms proposed by theinvention.

FIG. 2 shows a longitudinal section of the breech plug of the invention,having coupled thereto the O-ring seal in the perimetric groove locatedin the area corresponding to the front end of the breech plug.

FIG. 3 shows a longitudinal section of the breech plug located in anuncoupled position in correspondence with the rear end of the barrel ofa muzzleloader firearm.

FIG. 4 shows an elevational view of a tool configured to operate thebreech plug of the invention more comfortably and quickly.

PREFERRED EMBODIMENT OF THE INVENTION

In view of the indicated figures, it can be observed how in one of thepossible embodiments of the invention the quick-assembly breech plug formuzzleloader firearms proposed by the invention is a part of revolutioncomprising a cylindrical body (1) configured to be tightly coupledinternally in the rear end (10′) of a barrel (10).

The breech plug comprises a head (6) configured to define a limitcoupling position of the breech plug inside the barrel (10), as can beinterpreted in view of FIG. 3.

The cylindrical body (1) externally comprises a male thread (2) havingfour starts located close to the front end (3) of the breech plug,opposite the head (6), according to a plane perpendicular to an axis ofrevolution of the cylindrical body (1).

Said male thread (2) is configured to screw into a female thread (10″)located internally in the rear end (10′) of the barrel (10), as can beseen in FIG. 3.

As can be seen in FIGS. 1 and 2, the front end (3) of the cylindricalbody (1) comprises a smooth end section without male thread (2) having aperimetric groove (4) configured to house an O-ring seal (5).

Said O-ring seal (5) is configured to prevent firing gases from escapingthrough a clearance located between the cylindrical body (1) and thebarrel (10) when the firearm is fired and the breech plug is coupled inthe barrel (10).

According to a preferred embodiment of the invention, the O-ring seal(5) is made of an elastomer material configured to withstand highpressures and temperatures. For the purpose of maximizing the usefullife of the O-ring seal (5), it is covered with molybdenum bisulfategrease, the possibility of covering it with any other suitable greasefor its protection being contemplated.

As can be seen in FIG. 2, the front located in correspondence with thefront end (3) of the breech plug has a planar face for the purpose ofincreasing the resistance of the breech plug to withstand the largeactions to which it is subjected during the ignition of the firearm.

Likewise, the head (6) comprises a knurled side surface (7) in whichthere are located four blind holes (8) configured to receive a tooth(11′) comprised by a tool (11), depicted in FIG. 4, thus receiving thetransmission of a torque caused by the screwing and/or unscrewing of thebreech plug in the barrel (10), such tool being used in cases of jammingof the threads.

Finally, as observed in FIG. 2, the breech plug comprises an axiallycentered inner hole (9) configured to transmit the ignition of theprimer cap and the breech plug is coupled in the barrel (10).

In view of this description and set of drawings, the person skilled inthe art will understand that the embodiments of the invention which havebeen described can be combined in many ways within the object of theinvention. The invention has been described according to some preferredembodiments thereof, but for the person skilled in the art it will beevident that many variations can be introduced in said preferredembodiments without exceeding the object of the claimed invention.

1. Quick-assembly breech plug for muzzleloader firearms, comprising acylindrical body (1) configured to be tightly coupled internally in arear end (10′) of a barrel (10), wherein said breech plug comprises ahead (6) configured to define a limit coupling position of the breechplug inside the barrel (10), characterized in that the cylindrical body(1) externally comprises a male thread (2) having at least two startslocated close to a front end (3) of the breech plug, opposite the head(6), according to a plane perpendicular to an axis of revolution of thecylindrical body (1), said male thread (2) being configured to screwinto a female thread (10″) located internally in the rear end (10′) ofthe barrel (10), preferably 4 screw ridges.
 2. Quick-assembly breechplug for muzzleloader firearms according to claim 1, characterized inthat the front end (3) of the cylindrical body (1) comprises an endsection without male thread (2) having at least one perimetric groove(4) configured to house an O-ring seal (5) configured to prevent firinggases from escaping through a clearance located between the cylindricalbody (1) and the barrel (10) when the firearm is fired and the breechplug is coupled in the barrel (10).
 3. Quick-assembly breech plug formuzzleloader firearms according to claim 1, characterized in that thehead (6) comprises a side surface (7) in which there are located atleast one blind hole (8) and preferably 4 blind orifices, configured toreceive a tooth (11′) comprised by a tool (11) and receive thetransmission of a torque to cause the screwing and/or unscrewing of thebreech plug in the barrel (10) in the event of jamming thereof. 4.Quick-assembly breech plug for muzzleloader firearms according to claim3, characterized in that the side surface (7) of the head (6) isknurled.
 5. Quick-assembly breech plug for muzzleloader firearmsaccording to claim 1, characterized in that it comprise an axiallycentered inner hole (9) configured to allow the transmission of theignition of the primer to the charge of the powder (10).